James constant mcnabb



(No Model.)

J. o. McNABB. STOP COCK FOR AIR BRAKE SYSTEMS.

No. 523,081. Patented Jul 17, 1894.

EWV

l UNITED STATES PATENT OFFICE.

JAMES CONSTANT MONABB, OF MONTREAL, CANADA.

STOP-COCK FOR AIR-BRAKE SYSTEMS.

SREGIFIGATION forming part of Letters Patent No. 523,081, dated July 17,189 4.

Application filed July 18,1393. Serial No. 30,3 (N0 odel- To all whom itmay concern.-

Be it known that I, JAMES CONSTANT Mo- NABB, of the city of Montreal, inthe district of Montreal and Province of Quebec, Canada, have inventedcertain new and useful Improvements in Stop-Cocks; and I do herebydeclare that the following is a full, clear, and exact description ofthe same.

This invention relates to stop cocks applicable to railway air brakesystems and more particularly the angle cocks thereof, the obect beingto provide means which will prevent any tampering with the cooks thatcould have serious consequences or, as it might be otherwise expressed,to nullify the evil effects of any interference therewith as by closingthe valve of an angle cock and thereby cutting off the drivers controlof the brakes.

The invention may be said to consist in the construction of a stop cockwith a locking device or movable parts to prevent the movement of thevalve of the cook, the unlocking of which device will effect the escapeof the air, or other operative medium, and consequent application of thebrakes so that all danger is averted by the interference being madeknown. For full comprehension however of the invention, reference mustbe had to the annexed drawings forming a part of this specification, inwhich like symbols indicate corresponding parts, and wherein Figure 1 isa side elevation broken away of an angle cock with rotatable valve towhich my locking device is applied and Fig. 2 an enlarged horizontalsection of the same, also broken away.

I have chosen to show my invention applied to this form of stop cock forthe reason that its efficacy will in such a connection be more readilyapparent but it is equally applicable to all cooks for similar purposes.

A is the outer casing of the usual form of an angle cock of theWestinghouse air brake system, B its usual tapered valve with supportingspring 0 and handle 0 and D the usual recessed nut cap acting to holdthe spring and valve or plug in place, these however forming no part ofmy invention.

To carry out my invention in connection with thisform of stop cook alateral screw threaded opening e is made through the side of the casingA and another opening e, also screw-threaded, through the. side of valveB adjoining and in these openings the locking device preferably in theform of a plug F is located, its construction resembling a nut headedbolt with nut head f, a body having three channels g g 9 along itssurface extending from its inner end to within such a distance of thehead as will leave an intact or complete portion h sufiicient to securea thoroughly air tight joint when the plug is in its proper place, 2'.e. engaging and preventing any movement of the valve 13. It will thus beapparent that before the valve can be moved in any way the plug must bewithdrawn free of it and the channels g are made of such a length thatere the inner end of the plug has become disengaged from the valve anexhaust has been provided for the air through the three channels g thusefiectively preventing any ill consequences that might arise from thevalve being shut without the locomotive drivers knowledge.

While I have shown my locking device in k the form of a plug workingthrough an aperture in the valve casing yet I do not wish to be confinedto such an arrangement as I consider any movable part adapted when inone position to lock the valve against movement and by change ofposition to secure the es cape of the fluid controlled by such valvewithout any movement of this latter, as coming within the principle andscope of my invention,

The channels 9 being formed in the plug and the escape of the fluidthereby, when it is moved the required distance, impart to it a valvularcharacter and function which is an important feature of my invention.

What'l claim is as follows:

1. In a stop cook, a movable locking device adapted, when in oneposition, to lock the valve against movement and by change of position,to secure the escape of the fluid controlled by such valve without anymovement of the latter.

2. In a stop cook, a movable locking device in the form of a plugworking through an opening in the cock casing, constructed with such anopening, and adapted upon movement in one direction to engage and holdagainst movement the valve proper, constructed to receive it, and, bymovement in the direction required, to release the valve proper,securing the escape of said fluid before such valve is released.

3. In a stop cook, a movable locking device in the form of a channeledplug adapted when in one position relatively to the valve proper to locksame against movement and by change of position to secure the escape ofthe fluid controlled by such valve proper through itself.

4. In a stop cook, the combination with the plug thereof controlling thepassage of a fluid or like operative medium and suitable posts,- of amovable locking device in the form of a plug channeled for a portion ofits length,

